INFLUENZA AND THE INFECTIOUS DISEASES OF THE HORSE. 4-23 
The infectious germ seems to enter the nasal cavities first and 
then the bronchia, where its pathogenic action is felt. This ex¬ 
plains the peculiar and characteristic cough and the nasal dis¬ 
charge occurring in severe cases. 
In bovine typhus the mass of the blood becomes considerably 
diminished; the mucous membranes become pale; and the ane¬ 
mic animals need long rest and choice food. In typhoid fever, on 
the contrary, except in very severe cases, the animals recover 
rapidly. 
Though scalma begins in the first respiratory passages, and in 
the bronchia, it may be complicated witli exudative pleurisy, 
without leaving any marks of pneumonia to be detected at the 
post mortem. Fever does not follow a typical progress, as in 
pferdestaupe and brustseuche; its intensity is in proportion to the 
extent of the local disorders of the affected organs. For example, 
the temperature is much higher in cases of scalma complicated 
with pleurisy to double hydrothorax, than in simple inflammation 
of the first air passages. 
Lastly, it is to be observed that patients seriously ill consume 
relatively larger rations, without correspondingly gaining flesh 
and strength, than those which are more mildly affected, for the 
reason that the aliments consumed do not excite to the same 
degree the intestinal mucous membrane as they do in other infec¬ 
tious and toxic affections. 
Differential diagnosis .—Scalma cannot be mistaken for pfer¬ 
destaupe, because it often appears upon one or all the horses of a 
stable which had, at a shortly previous period, been affected with 
the latter disease. In other words, it is seldom that the same 
subject is affected twice with pferdestaupe, and never has the 
reappearance of this disease been observed upon all the horses of 
the same stable. 
Again, scalma is not, like pferdestaupe, communicable by 
simple contact of a healthy animal from one stable with a dis¬ 
eased one from another. 
Lastly, the autopsy of scalmatical horses does not reveal sub¬ 
cutaneous, serous or sub-mucous infiltrations ; the contrary being 
the fact in'respect to the other disease. 
